Clothes drier



Dec. 27, 1955 CLOTHES DRIER Original Filed Feb. 3, 1951 J. H. ROBINSONETAL 3 Sheets-Sheet l Inventors John HRobinson;

Paul L Paulseh 1955 J. H. ROBINSON ETAL 2,728,481

CLOTHES DRIER Original Filed Feb. 3, 1951 3 Sheets-Sheet 2 InventovsJohn H. Robinson,

Paul L. Paulsen, 5 Their Airborneg.

Dec. 27, 1955 J. H. ROBINSON EIAL 2,728,481

CLOTHES DRIER Original Filed Feb. 3, 1951 3 Sheets-Sheet 3 InventorsJohnH. Robinson, Paul L. Paulsen,

T heir Attorne 5.

CLOTHES DRIER John H. Robinson, Buechel, and Paul L. Paulsen, Lyndon,

Ky., assignors to General Electric Company, a corporation of New YorkOriginal application February 3, 1951, Serial No. 2119,280. Divided andthis application June 19, 1953, Serial No. 362,732

3 Claims. (Cl. 220-4) Our invention relates to a clothes drier of thetumbler type, and in particular to a drier adapted for domestic use.

This application is a division of our copending application Serial No.209,280, filed February 3, 1951, now Patent No. 2,707,837, issued May10, 1955, and assigned to the General Electric Co., assignee of thisapplication.

We have directed our invention primarily to the objective of providing aclothes drier having a simplified construction capable of eflicientperformance over a long life span, arranged for easy servicing bymechanically unskilled persons.

..More specifically, the objects of our invention include the provision6f an air distribution system which improves heat transfer by forcedconvection and conduction and minimizes the accumulation of lint indiflicultly accessible areas within the drier; a simplified heaterchamber construction which provides a tumbler shaft supporting structureof substantial rigidity; and an improved construction which facilitatesmanufacturingof. an improved machine at a lower cost.

. In a presently preferred embodiment of our invention we mount aforaminated tumbler within a heated,'insulated chamber for rotation-on anon-vertical axis. At a lower corner of the chamber there is provided anair duct extending the full length thereof; by suitable fan means wedevelop within the duct an air pressure somewhat above that of thechamber atmosphere. This air is substantially at room temperatureandidischarges into the heater chamber as sheets or curtains of air, oneof which flows about the tumbler counter to the direction of rotationthereof, while another conforms generally to the direction of rotation,impinging angularly against the bottom of the tumbler.

.In accordance with one of the features of this invention, we provide asimplified and improved construction in which end panels for the heaterchamber are secured to a base. The sides and roof are formed by a singlewrap-around sheet of material with V-shaped marginal flanges to receiveedges of .the end panels when drawn into position and anchored to thebase. The wraparound sheet carries an insulation blanket which is heldin place by the same anchoring means extending into the base. By thisarrangement, the Walls defining the heating chamber also define ineffect a large hollow structural beam for aiding in support ofthe.drier. drum in cantilever fashion.

Other features and advantages of ouninvention will be better understoodfrom the, following detailed .description of the presently preferredembodiment as'illustrated in the accompanying drawings, in which .Fig.-l is a front elevation of one form of. drierembodying our invention,certain casing portions having beenbroken away to reveal underlyingstructure; Fig. 2'is.a rear 'elevation of the drier, certain portionsbeing broken away; Fig. 3 is a side sectional elevation of the drir. ofFig.1 on line 3-3 ofFig. 1; Fig.4 is a detail in sectional elevationshowing a method ofconstructirig the heater cha n;

ttes atentO her and securing the insulation thereto; and Fig. 5 is acorner construction detail showing a method of insulation securement andapplication of the top wall portion of the outer housing.

Referring to the drawings, the general structure of a drier embodyingour invention comprises an outer'housing 1 having conventional unitarywall panels arranged in wrap-around fashion on a suitably reinforcedfootprovided base 2. The rear panel 3 is attached to side wall flangesand to the base 2 by removable fastenings to provide for easy access tothe drive mechanism, later described. A cylindrical sleeve 4 extendsinwardly from the rectangular recessed front housing wall portion 5within which a door 6 seats when closed. The dooris preferably gasketedby a resilient strip 7 which compresses against the front wall panelwhen the door'is latched in closed position by conventional means (notshown). The gasket prevents the escape of lint during the operation ofthe drier. We prefer to hinge the door by concealed hinges 8. As usual,the door may have a transparent window 9 through which the interior ofthe drier is visible. The front panel overhangs the base as shown bestin Fig. 3 to provide toe space, and the lower front casing portiontherefore conveniently comprises an angle strip 10, hereinafter called atoe-board panel, to the projecting portion of which the bottom edge ofthe front casingwall is fastened.

Integration of the five'sides of the housing above the base isaccomplished in'a manner which provides a simple, rigid assembly. Aspresently constituted, the upper edge portions of the front and sidewalls of the housing are inwardly flanged to support the similarlyflanged front and side edges of the top panel 11. Tablike extensions 12of the top panel front flange act as base 2. For the cylindrical tumblertype of drier presently.

exemplifying our invention, we employ eccentrically horseshoe-shapedfront and rear panels 16, 17, flanged at their lower ends to befastenedto the base wall structure 2 as seen in Fig. 3. Each panel isappropriately apertured to accommodate various operating components; forexample, the forward wall 16 has a projecting flangedended cylindricalaperture 18 which secures to the front outer casing panel about thesleeve 4, with respect to which the aperture is concentric. We prefer togasket the connection between the-respective front panels of the heatercasing and outer casing. About the front and rear panels, 16, 17, wewrap a metal sheet 19, the forward and rear edges of which are flangedto overlap the peripheries of said panels in a socket-like arrangementshown best in Fig. 5. necessary mechanically to secure the sheet 19 tothe front and rear panels. A convenient manner of afiixing the sheet 19to the base 2 is shown in Fig. 4. The lower side edges 20 of the sheetare shaped to providea -resilient bead which rests upon a base wallportion 21 0th.

set to the required angularity. Machine screws 22 passing throughaligned apertures in the beads 20 into tapped holes in base wall 21.draw the sheet 19 securely into position.

The resilience of the beads 20 affords a yieldability whieh compensatesforminor irregularities of alignment;' the reaction of the beads alsoprovides a lock-nut, effect Such arrangement makes itllll-x which holdsthe screws 22 against loosening. We insulate the heater chamber withconventional materials such as glass W011 pads or batts. The insulationadjacent sheet 19 is conveniently held in place by straps 24 which areclamped against the respective base offsets 21 by the beads and screws22. Front and rear wall insulation is held in place by tabs 25 extendingfrom sheet 19 over the front and rear panels 16, 17, as illustratedclearly by Figs. 3 and 5.

Heater 26 is an integrated assembly, preferably embodying a channel-likeframe 27 from which project a suitable number of insulators 23 on whichthe resistance wire 30 is convoluted over an area which extendssubstantially the whole length of the heater chamber. A reflecting sheetmay be fixed back of the heater coil, and we guard against directcontact of lint with the coils by providing a guard screen 32 (Fig. 3),the mesh of which is sufficiently large to pass radiant heat insubstantial quantity. The heater assembly is passed through an opening33 in rear panel 17 of the heater chamber and is supported on memberssecured to panel 17 and to front panel 16 by screws engaging the severalbrackets 34a. At the rear panel 17 the insulation blanket is suitablyarranged to provide a space for a binding post plate 35 of insulatingmaterial which carries the heater coil connection terminals 36.

Panel 17 is set sufficiently forward of outer housing panel 3 to providea relatively deep rear compartment which accommodates the tumbler drivemechanism and serves as an air admission chamber communicating by way ofthe louvres 38 with the outer atmosphere. Tumbler 40, whichillustratively is of the horizontal axis cylindrical type, hasimperforate front and rear walls 41, 42 and a foraminated peripheralWall 43. The front wall has a short neck 44 which extends in concentricoverlapping relationship with the collar 4.

It will be noted that tumbler is supported only at its rear end.Accordingly, We impart rigidity by inwardly dishing a relatively largecentral area of rear wall 42 and secure the center of said wall portionby rivets or the like to the flanged end of an enlarged head portion oftumbler shaft 45. We also provide a dished reinforcement plate 46riveted to rear wall 42 and secured to the drive shaft in spacedrelation with respect to said wall 42.

Ribs 47 (only one shown in Fig. 3) supplement the usual plurality ofconventional triangular tumbling ribs 48 in tumbling and flufling theclothes as the cylinder is rotated. The tumbler support structurecomprises a rigid relatively wide channel 50 bolted through base 2 to aheavy plate 51 (see Fig. 2) and preferably riveted through its web toheater chamber panel 17. A stiffening angle member 52 is affixed to theupper end of channel 50 as shown in Fig. 2 and extends transverselyacross the rear panel 17 to which it also is secured. The ends of theangle member 52 extend to, or slightly beyond the marginal edges of theheater chamber side wall panel. Thus, the forward thrust of the channel50 occasioned by the weight of the tumbler and its contents is opposedby the very substantial resistance to distortion of the heater chamberwhich acts as a large box girder firmly affixed to the base 2.

The shaft and tumbler supporting means comprises a relatively heavysleeve 53 which rests within a centering notch 54 (Fig. 2) provided inthe upper end of channel 50 and within the similarly notched rear wall55 of a bracket 56 fixed to the side flanges of the channel andprojecting rearwardly therefrom. The web of the channel and the saidrear wall 55 provide relatively widely spaced support points. A saddleclamp 57 secures the sleeve in position. Within the sleeve we providesuitable bearings 58, 60 (Fig. 3) preferably of the oil impre natedtype, within which shaft 45 rotates.

Drive motor 61 may be mounted on base 2 with a conventional resilientbearing cradle as shown. Reduction 4 from the 1725 R. P. M. motor speedto the 50 R. P. tumbler speed may conveniently be accomplished by beltdrive through an idler sheave system in which the idler 62 is beltconnected to drive sheave 63 on the motor shaft and is in turn connectedthrough its associated sheave 64 to sheave 65 fixed to shaft 45. tensionwe support sheave 62 on an idler bar 66 passing through openings ofsuitable dimension in angle member 52 and a second angle member 67secured to rear panel 17 below the level of shaft 45 and at one side ofchannel 56, as clearly appears in Fig. 2. The openings are sizedrelative to bar 66 and aligned with respect to each other in suchfashion that under the bias of the spring 68 the bar is urged downwardlyand to the left of Fig. 2 and has a limited freedom of lateral planerotation relative to the respective sheaves. Such single unit belttensioners are well known in the art and we make no claim thereto.

The air distribution system includes a plenum or pressure chamber fromwhich air flows into the heater chamber, and a lint trap through whichit is exhausted. The plenum chamber, as seen in Fig. 1, comprises thebase 2 and lower portion of the heater chamber side wall sheet 19 inassociation with a side wall plate 70 and a roof plate 71, each of thelatter plates extending the full length of the heater chamber forsecurement to the end wall panels thereof. As appears in Figs. 2 and 3,the motor 61 is mounted in the plenum chamber and its shaft carries thefan 72 which operates in the plane of an opening 73 formed in the rearwall panel 17. The fan draws air through louvres 38 into the plenumchamber from which it discharges under pressure through two relativelynarrow slots 74, 75, which are substantially parallel to the tumbleraxis. Each air discharge is sheetlike. Slot 74 directs air upwardly tofollow the side wall sheet 19 of the heater chamber in a directioncounter to the rotation of a tumbler whereas the air discharging from 75impinges against the bottom of the tumbler in the direction of tumblerrotation. These air slots are conveniently formed by spacing the edgesof the plate 71 with respect to the side wall plate 70 and the side wallsheet 19, and, therefore, extend the full width of the heater chamber.The upwardly traveling air sheet or curtain envelops the heater unit 26and abstracts heat therefrom and incidentally serves to cool the sidewall and roof portions of the heater chamber reducing the insulationrequirements thereof. In the domestic type clothes drier exemplifiedherein, the heater coil is rated at approximately 4400 watts. The metalchannel-like housing for the coils absorbs a substantial amount of heatwhich is transferred to the air flowing thereabout. The turbulencecreated by the relatively rough peripheral wall of the tumbler improvesheat transfer from the air to the tumbler wall and the pump-like etfectof the motion of the clothes within the tumbler produces an interchangeof the external heated air and the humid air volume which builds upwithin the tumbler. The tumbler and contents also benefit by thesubstantial amount of radiant heat of the heat coils reflected towardthe tumbler by the reflector plate 31.

As is well known, laundry which is taken from a domestic washing machineafter having been damp-dried by centrifuging or run through a wringerhas a moisture content which may be equal to or more than the dry weightof the clothes according to the efliciency of the damp-drying devices.Assuming a conventional nine pound washer load, it is apparent that theclothes when w For maintenance of belt ticles of laundry during thetumbling thereof. The .air stream discharging through slot 75, beingcool and flowing about the lower left quadrant of the tumbler as viewedin Fig. 2, reduces the temperature of air discharging from the tumbler.During the later portion of the drying operation, such a temperaturereduction is very desirable, particularly when the drier discharges intothe room in which it is located.

The discharge from the heater chamber is through a suitable linttrapping device, as described in greater detail in our above-citedcopending application Serial Number 209,280, new Patent No. 2,707,837.As shown herein by Figs. 1 and 3, moist air exhausts through thetoe-board panel which is provided with a relatively long eccentricallydisposed opening snugly to receive the lint trap, which preferably is adrawer-like structure including a base panel from which sides 77 extendupwardly, and an upwardly-sloping mouth structure 78. We provide a linttrap screen 82 suitably arranged in a frame 83. Itis intended that theuser periodically remove the lint trap to brush or otherwise clean theaccumulation of lint on the screen. However, in consideration of thepossibility that this may not be done we provide a port 88 (Fig. 3) inthe respective walls 77 so as to insure the discharge of air from theheater chamber even in the circumstance that the lint trap screen issubstantially blocked by a lint accumulation. The rear heater chamberpanel 17 is provided with an opening over which a cover plate 97 isremovably applied. It will be observed from a comparison of Figs. 1 and2 that the opening in panel 17 is of substantially less width than theopening in the toe board 10 necessary to accommodate the lint drawer.The purpose of this is to utilize conventional air duct sizes, forexample, approximately 3 /2 in. deep by 10 in. wide in the ductwork forthe rear discharge trap arrangement. The rear edge walls of the drawerhowever also fit snugly against the panel 17. The rear casing panel 3has an opening provided with a removable cover plate 98, said openingand cover plate being slightly larger than the opening and cover plate97 of the panel 17 as best appears in Fig. 2. When a rear dischargesystem is to be utilized the respective cover plates 97 and 98 areremoved and a duct section sufficient to extend suitably beyond the rearcasing 3 is inserted through the rear casing opening and is secured tothe chamber wall 17 by screws or equivalent passing through the inwardlydirected flanges of the extension. The size of the duct extension issuch that the mechanic may easily reach through it to complete thefastening. Further duct extensions may be aflixed by conventional slipfit elements, not shown.

In all tumbler driers of which we have knowledge, some lint willaccumulate within the heater chamber; not all of the lint remainssuspended in the air stream discharging through the lint trap. Weappreciate that this will also be true in a drier constructed accordingto our invention as above described. However, we effectively minimizethe accumulation of lint in ditficultly accessible portions of thechamber by the relationship of the plenum chamber and the direction ofair discharged therefrom to the tumbler and its direction of rotation,as well as by the horseshoe slope of the casing defined by the wallpanels 16 and 17 and the enclosing sheet 19, which shape makes itpossible to avoid having narrow lint trapping passages between thecasing and the lower portion of the tumbler 40. The disposition of theair slots 74 and 75 creates a small quiet air zone immediately above andin the right of the plenum chamber roof panel 71 as viewed in Fig. 2.The air curtain from 74 follows up along the wall 19 until loss ofmomentum causes it to diffuse around the heater assembly, and the forceof discharge through slot 75 reduces turbulence which might produceback-flow over the panel 71. The slope of roof panel 71 toward thetumbler and the direction of rotation of the tumbler establishes acondition in which the tumbler acts as an airpumpwhich prqduces a;relatively gentle ain flow through the throat formed by the convergenceof the tumbler and the roof panel. .The diffusing curtain from slot 74maintains a sufficient turbulence about the upper portion of the tumblerand the heating unit to preclude lint from settling thereon. Lintwhichmay be carried through the lower portion of the tumbler by themechanical action of the clothes movement therein will be mechanicallytransported into the quiet zone area where some of it will deposit onthe roof panel 71. Eventually the air movement induced by the tumblersweeps the lint into the air flow discharging from 75 and it will becarried by said air flowtoward the lint trap. The air' discharge .fromorifice 75 sweeps the bottom portion of the tumbler and removes lintwhich may have adhered thereto; The air movement through the orifices 74and 75 provides a discharge pattern which minimizes lint accumulation indiflicultlyaccessible portions of the heater, chamber. Accordingly, thechamber. may easily be cleaned with conventional vacuum cleaneraccessory tools.

A suitable drier control is provided as described in detail by ourcopending application Serial No. 209,280, now Patent No. 2,707,837,referred to above. For clarity, these details have been omitted fromthis application, and we have shown only a thermostat control 107 and anon-ofi and drying period control knob 106 (Fig. 1).

As best shown in Fig. 3 the temperature sensitive bulb 108 forthermostat 107 is located suitably within the heater chamber to sense anaverage temperature therein. The location shown in Fig. 3 may notactually be that selected for the bulb; some experimentation may berequired to determine the most advantageous standardization of bulblocation. It will be understood that the thermostat is the type whichcloses its circuit when the bulb temperature is below the setting point.A protective fuse (not shown) may be concealed beneath the toe boardledge behind a swingable cap 116, pivotally affixed to the toe boardledge and secured by a thumb nut 117, see Fig. 1. It will be understoodthat the rear of cap 116 is open and that when the cap is on homeposition, the rear. wall of the toe board completes the fuse headenclosure. For illumination of the interior of the heater chamber andthe tumbler, we provide an incandescent lamp 118 socketed within theplenum chamber behind a removable window 120. An ozone producing lamp121 similarly within the plenum chamber tends to give the air within thechamber a fresh outdoor odor which is to some extent imparted to theclothes.

While we have shown a particular embodiment of our invention, it will beunderstood, of course, that we do not wish to be limited thereto sincemany modifications may be made; and we, therefore, contemplate by theappended claims to cover any such modifications as fall within the truespirit and scope of our invention.

What we claim as new and desire to secure by Letters Patent of theUnited States is:

1. In a drier for fabrics and the like, a heater chamber comprising abase, end-wall forming panels secured to and extending from said base inmutual alignment, side and roof-forming means including a resilientmetallic sheet wrapped over peripheral edges of said panels and havingmarginal flanges providing a pocket having a substantially V-shapedcontour within which said edges of the respective front and rear wallpanels are disposed,

- and means for drawing said sheet about said end panels to confine theedges thereof snugly within said pocket, said means including asubstantially semi-cylindrical edge portion integral with said sheet atthe other marginal edge portions thereof andfastening means extendingchordally through said semi-cylindrical edge portions to compress thesame against said base.

2. In a drier for fabrics and the like, a heater chamber comprising abase, end-wall forming panels secured to and extending from said base inmutual alignment, side and roof-forming means including a resilientmetallic sheet wrapped over peripheral edges of said panels and havingmarginal flanges providing a pocket having a substantially V-shapedcontour within which said edges of the respective front and rear wallpanels are disposed, means for drawing said sheet about said end panelsto confine the edges thereof snugly within said pocket, including abottom edge portion of semi-cylindrical configuration at each side ofsaid sheet extending between the front and rear panels and fasteningmeans passing through said semi-cylindrical edge portions into saidbase, a Wall of insulation material disposed about said sheet, andsecurement means for said insulation wall comprising strap meansextending continuously about said sheet and secured beneath each of thesaid bottom semi-cylindrical edge portions.

3. In a drier for fabrics and the like, a heater chamber comprising abase, end-wall forming panels secured to and extending from said base inmutual alignment, side and roof-forming means including a resilientmetallic sheet wrapped over peripheral edges of said panels and havingmarginal flanges providing a pocket having a substantially V-shapedcontour within which said edges of the respective front and rear wallpanels are disposed, and means for drawing said sheet about said endpanels to confine the edges thereof snugly within said pocket, saidmeans including a springable edge portion formed on each side of saidsheet extending between the front and rear panels and fastening meanspassing through said springable portions into said base.

References Cited in the file of this patent UNITED STATES PATENTS1,066,215 Murray July 1, 1913 1,943,255 Booth Jan. 9, 1934 2,046,810Cannon July 7, 1936 2,271,260 Horsley Jan. 27, 1942 2,540,955 Moore Feb.6, 1951 2,644,245 Hammell et al. July 7, 1953

